Originally posted by TimT
Many of the systems now can be based on manifold pressure (speed density), or throttle position (alpha-n) or a combination of the two. Wild cams screw up vacuum signals, you can set up mixed scheduling until you get into boost. etc...
S/D is great on a boosted car for just this reason - MAFs can lose accuracy in big cam, and/or forced induction use. If you have a good handle on all of the parameters needed, and you're not planning on changes (like stronger cams or increased compression, etc.) S/D is the ticket as you set it up once and you're done.
Tha MAF adds some flexibility, but possibly at the expense of some response/drivability....